Why validation & accuracy matter for geocoding APIs
Choosing the right geocoding service is the first step toward unlocking better location intelligence and helping your organization make more strategic decisions.
From our ebook, we’ll cover two key questions to ask when choosing a geocoding API:
- Does the API include address validation
- How accurate are the geocodes?
Question 1: Does the geocoding API include address validation?
Fitness advocates are fond of saying things like “Abs are made in the kitchen” and “Fuel your body for success.” Our kitchen still hasn't produced any abs, but they’ve got one thing right, if you put garbage in, you’re going to get garbage out, even when it comes to geocoding!
The data you get from any geocoder is only as good as the data you put into it. That’s why one essential feature to look for in a geocoding API is built-in address validation.
Address validation is the process of verifying an address against an authoritative database to confirm if the address is a real place.
Why does address validation matter?
20% of addresses entered online contain errors. Turns out, not everyone paid attention in keyboarding class or suffered through “Mavis Beacon Teaches Typing” in computer lab. And with today’s phone touch screens making it easy to “fat finger” the on-screen keyboard, well, address validation is critical!
Unfortunately, not all geocode providers perform the essential first step of address validation. Without validation, 20% bad address data can lead to 20% bad geocodes—including geocodes for addresses that don’t actually exist or are miles away from the real location.
Geocoding without address validation can result in:
- Misdelivered shipments and failed service calls
- Increased difficulty in market segmentation, accumulation, and exposure analysis
- Missed sales opportunities
- Mismanagement of territory boundaries
- Increased data management costs
All of these consequences will cost your organization time and money! Plus, if the geocoding API you’re considering doesn’t include built-in address validation, you’ll need to pay extra for an additional address verification service to clean up your data first. Keep that in mind when comparing geocoding API costs.
Question 2: Does the API provide “as advertised” accuracy?
Geocoding unlocks hidden business value from your address data. The knowledge you can glean from location intelligence is beneficial for risk management, regulatory compliance, pricing, and long-term strategic planning. But address data is useless if it isn’t accurate.
To determine if you’re choosing the most accurate geocoding API, you need to ask about match rate, geocoding accuracy, and cascading match logic.
Match rate
The match rate, or number of addresses that were recognized and precisely geocoded, is what matters to your business operations. The higher the match rate, the more confidence you can have in making business decisions based on the data you’re getting from geocoding.
Geocoding accuracy
Rooftop-level accuracy is the paragon of geocoding. Other, less precise, levels of accuracy include a geocode to the nearest street intersection, a Parcel Centroid, a ZIP Code, city, or State Centroid.
Why does precision matter in geocoding? Knowing the precise location of the primary structure on a parcel can make a huge difference when it comes to insurance quotes, city planning, telecommunications, and more. Even being off by just a dozen feet could seriously skew the results.
Many providers advertise their location accuracy as “rooftop geocodes.” However, there’s no ruling body or ultimate authority that defines “rooftop-accuracy.” Each provider interprets it a little differently. These disparate definitions of “rooftop-accuracy” make it difficult to compare levels of accuracy simply by the term “rooftop” alone. None of the above are even truly rooftop accurate!
If every provider defines rooftop-accuracy a little differently, how do you find out if the geocodes provided are truly rooftop accurate or simply advertised that way?
Geocoders generally allow free test lookups for benchmarking—this is the best way to determine accuracy levels. Inaccuracies become more apparent as parcel size increases. By geocoding farms, large parcels, and plots with irregular boundaries, you’ll easily find the most accurate geocoders.
Cascading results
Many geocoding services use “Cascading match logic” to provide the greatest number of matches—and the highest accuracy available for matches made. To do this, the API runs addresses against multiple conflated datasets, starting with the most accurate. It could, for example, match addresses against the following data levels (if available):
- Rooftop address point
- Parcel centroid
- Street address interpolated
- ZIP+4 accuracy
- ZIP+2 accuracy
- Street centroid
- 5 digit ZIP Code centroid or city centroid
As we mentioned earlier, Rooftop Address Point is the most accurate and is the gold standard for quality geocoding.
A good geocoding API using cascading match logic would:
- Look for rooftop address point matches.
- If a rooftop address point isn’t found, a second and third pass would look for parcel centroid and street address interpolated level matches.
- Any addresses still unmatched would be run against ZIP+4, ZIP+2, street centroid, and 5 digit ZIP Code and city centroid.
After matching, the level of accuracy attained should be clearly stated in the output. After all, a geocode that accurately marks the rooftop of a home and a geocode that marks the center of a city cannot be compared apples to apples, and doing so would greatly skew your data analysis.
Bad data quickly leads to flawed business decisions and outcomes. Prevent problems before they appear by choosing the right geocoding API for your needs.
To get even more details about address validation and geocoding API accuracy, download the full ebook, “8 Questions to Ask When Selecting A Geocoding API” today!
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Andrew Townsend